Hydroxylamine compounds have a variety of useful applications. Generally speaking, hydroxylamine compounds are strong reducing agents. Accordingly, hydroxylamine compounds are useful in stripper formulations. Stripper formulations may be used to remove photoresists from or clean a substrate. For example, hydroxylamine stripper solutions are used to remove developed photoresists, such as patterned polyimide from metal foils. Hydroxylamine stripper solutions are extensively utilized in the printed circuit board fabrication and microelectronic chip fabrication technologies. Hydroxylamine compounds are also useful as intermediaries in chemical processes, especially in the pharmaceutical and agricultural industries.
Frequently, solutions of hydroxylamine, especially solutions prepared from hydroxylammonium salts, contain undesirable amounts of impurities such as salts including hydroxylammonium salts and acid salts, various metals and metal ions, ammonia and unwanted organic materials. Thus, there also exists a need for hydroxylamine solutions having high purity. There exist several production methods to manufacture hydroxylamine compounds.
Some of these methods, however, do not provide hydroxylamine compound solutions of high purity which some applications of the compounds require. While some purification schemes exist, ultra high purity hydroxylamine compound solutions are either difficult to find or expensive to make. Consequently, there remains a substantial demand for large quantities of high purity hydroxylamine compound solutions.